Rectifier is an electronic device used to convert alternating current (AC) voltage to direct current (DC) voltage. It is a crucial component in many electronic devices and power supplies that require a DC voltage supply.

Working of a Rectifier:
A rectifier consists of one or more diodes that allow current to flow in one direction only, blocking the reverse current. When an AC voltage is applied to the rectifier, it passes through the diodes, which allow only the positive half-cycle of the AC waveform to pass through and block the negative half-cycle. As a result, the output voltage is pulsating DC voltage.

Types of Rectifiers:
There are two types of rectifiers: Half-wave rectifier and Full-wave rectifier.

1. Half-wave rectifier: In a half-wave rectifier, only one diode is used to convert the AC voltage to DC voltage. The output voltage is pulsating DC voltage with a voltage drop equivalent to the forward voltage drop of the diode.

2. Full-wave rectifier: In a full-wave rectifier, four diodes are used to convert the AC voltage to DC voltage. The output voltage is a smoother DC voltage with a voltage drop equivalent to the forward voltage drop of the diodes.

Applications of Rectifiers:
Rectifiers are used in a wide range of applications, including:

- Power supplies for electronic devices
- Battery charging circuits
- Welding machines
- Electroplating and electrolysis
- X-ray machines
- Radio and television receivers
- Lighting systems

In summary, a rectifier is an electronic device used to convert AC voltage to DC voltage. It is an essential component in many electronic devices and power supplies that require a DC voltage supply. Rectifiers can be either half-wave or full-wave and are used in a wide range of applications.